We investigate different linear effects that appear in the light beam propagation behind a three-dimensional woodpile photonic crystal. On one hand we report and analyse experimental observation of narrow and well collimated laser beam formation behind the photonic crystal. We show that this collimation depends on the input laser beam focusing conditions. On the other hand we also report the first theoretical and numerical observation double imaging formation behind the photonic crystal. That conclusion comes from the idea that the spatial dispersion possess multiple branches (Bloch branches), generally of different curvatures, for a fixed frequency.

The authors acknowledge support from the Spanish Ministerio de Ciencia e Innovacion and European Union FEDER through projects FIS2008-06024-C03-C02, and FIS2011-29731-C02-01, by EC Seventh Framework Programme LASERLAB-EUROPE (grant agreements no 228334), and by European Union Structural Funds project 'Postdoctoral Fellowship Implementation in Lithuania'.